Integrated circuit flat packs are exceedingly small. They are manufactured in the millions and are commonly placed in individual carriers that protect them during subsequent handling steps. While in the carriers, the integrated circuit flat packs can be marked and tested, for example.
Presently known integrated circuit carriers can require rather complex mechanisms for inserting the integrated circuit flat packs into the carriers. Carriers that connect to the body of the integrated circuit can interfere with subsequent marking of the flat pack body. Carriers that connect to the body of the integrated circuit also can experience difficulty in properly connecting to the body of the integrated circuit, or they can inadvertently rupture the seal of a flat pack body which tends to be brittle.
It is common practice to remove integrated circuit flat packs from their carriers to mechanically bend the leads into desired configurations for subsequent connection to printed circuit boards. The integrated circuits, after the leads are bent, are commonly placed in trays, rather then being reinserted into their individual carriers. Many presently known carriers prevent integrated circuits, which have had their leads bent, from being reinserted into the carriers. Thus, carriers are not available to protect the integrated circuits once they are removed and the leads modified.
Presently known integrated circuit carriers are disclosed in U.S. Pat. No. 3,409,861 to Barnes et al., U.S. Pat. No. 3,529,277 to Barnes, and U.S. Pat. No. 3,652,974 to Tems. These patents relate to integrated circuit carriers that connect to the body of the flat pack. My U.S. Pat. No. 4,379,505 represents an improvement over these integrated circuit carriers.
The integrated circuit carrier disclosed in my U.S. Pat. No. 4,379,505 is used with a simplified mechanism for inserting the integrated circuit flat pack into the carrier. The carrier connects to the leads of the integrated circuit rather than the integrated circuit body; and as a result the integrated circuit body is completely exposed at the top of the carrier for subsequent marking or other handling steps. The carrier also facilitates removal of the flat pack from the carrier, bending of the leads into desired configurations, and reuse of the flat pack carrier by reinserting the flat pack into the carrier. Even though the leads have been bent or have otherwise had their configuration modified, the flat pack still can be reinserted into the carrier.
The integrated circuit carrier disclosed in my U.S. Pat. No. 4,379,505 patent has elongated fingers extending diagonally inwardly from the four corners of a rectangular opening in the carrier. The flat pack is quickly and easily inserted into the carrier by automated equipment using vertical pins to push the fingers apart sufficiently to allow the flat pack body to be inserted in the opening in the carrier, after which the vertical pins are retracted to allow the fingers to bend back to their original positions for connecting to the outermost leads of the integrated circuit. However, bending the fingers of the integrated circuit carrier can adversely affect the ability to reuse the carrier. That is, as long as the carrier (especially the fingers of the carrier) are made from a reasonably highly resilient material, the fingers will have sufficient "memory" to return to their original positions after the bending force is removed. If they do not return to precisely their original positions then they may not properly connect to the leads of a subsequent integrated circuit when the carrier is later reused. The carrier disclosed in my U.S. Pat. No. 4,379,505 patent required a high memory resilient material, but such a material also is a disadvantage. It is important to provide an anti-static carrier and it is common to load the plastic carrier material with carbon or other fillers to increase electrical conductivity so the carrier material will quickly discharge static electricity. However, addition of such fillers decreases the ductility of the carrier, and decreased ductility results in a similar decrease in the flexibility of the retaining fingers that connect to the leads. If the integrated circuit carrier disclosed in my patent is made from such an anti-static material, the retaining fingers are not sufficiently resilient to have the memory required to allow the carrier to be reused more than about once or twice.
The present invention provides an improved integrated circuit carrier having retaining fingers that connect to the leads of the integrated circuit flat pack. The retaining fingers are configured and arranged such that they maintain a high resiliency with good memory, even though the carrier is made from low ductility anti-static materials. The improved flexibility and memory of the retaining fingers makes it possible to re-use the integrated circuit carrier a large number of times, many more than the carrier disclosed in my U.S. Pat. No. 4,379,505 patent. Other advantages also are provided and are described in detail below.